What aspects are used to check whether the film panel is qualified

The membrane switch needs to be inspected during raw materials, production, and after production to ensure that the produced membrane switch is qualified and meets the requirements. Membrane switch manufacturers have always been strict with themselves in order to produce high-quality membrane switch panel products. Below, we will learn about the aspects in which membrane switch panels should be inspected to see if they are qualified.

1. Appearance: Combination state: There should be no residual data chips, foreign objects, stains, height, grease attached to the exterior and interior, fingerprints on the circuit, or burrs on the punched exterior. Scar: All circuits and contacts must not have cutting marks that penetrate the surface (i.e. cutting marks from the circuit to the substrate). Minor abrasions are also based on the principle of not affecting their impedance. The surface of carbon ink is prone to scratches, which should not affect the conductivity of the circuit. Foreign objects: The circuit must not have any foreign objects attached to it.

2. Line conductor section: Conductor thickness: The conductor thickness is usually controlled between 7-12 μ m and should be uniform and lubricated. Defects and pinholes in conductors: According to the following diagram specifications, one should be allowed within each 50mm range. Carbon ink: The carbon ink that covers the silver paste circuit should ensure that the silver paste is completely covered, with a thickness of 8-10 μ m and no significant silver paste protrusions. Breaks and short circuits: It is not allowed for conductors to have any signs of breakage or short circuits.

3. Insulation printing: All touch points of film switches must not have any insulation ink attached, and the insulation ink surface should be flat to prevent any defects such as bubbles or pinholes from affecting the insulation function. Adhesion strength: After the insulating ink dries, the ink surfaces should be pressed against each other for 24 hours to ensure that the insulation does not stick to each other. After applying pressure sensitive tape without bubbles for 1 minute, it should peel off quickly without any ink falling off. Jumper: All jumper parts are designed according to the requirements of the line conductor, and all jumper products must pass 100% open circuit, short circuit, and insulation resistance tests. Ensure that there are no open circuits, short circuits, and insulation resistance greater than 500M Ω (500VDC for 1 minute).

4. Mechanical properties: Stamping burrs and mold extrusion bending scale: Stamping burrs and extrusion bending scale should not exceed 0.2mm, and the orientation should face the side without conductors. The orientation deviation of the upper and lower lines: The middle orientation of each switch contact of the upper and lower lines should be offset from each other by a tolerance of 0.5mm.

5. Raw materials: substrate, silver paste, carbon ink, spacer, adhesive, bonding glue, reinforcing plate, insulation printing should comply with the drawing rules.

6. Shape: The shape, conductor line, insulation treatment, lining plate combination, etc. should conform to the drawing rules or provide material samples.

The above are several aspects of membrane switch inspection. If you need to order membrane switch panels, please contact us.